1. Technical Field to which the Invention Belongs
The present invention relates to a windmill device that is rotated by wind power and converts rotating energy into other energy such as electric energy, and more particularly to an improvement of a three blade type vertical windmill device that can efficiently obtain the rotating energy irrespectively of a wind direction, is silent so as not to mind its wind cutting sound more than a usual propeller type windmill device and eliminates an anxiety about the generation of noise even when the windmill device is disposed in a home.
2. Prior Art
As a power generation device for obtaining small electric power, for instance, a wind power generation attracts attention in view of an advantage that an environmental contamination does not arise. In the case of a usual wind power generation device, a wind generation device having a propeller provided on a horizontal shaft has been ordinarily employed. In such a wind power generation device, the propeller needs to be directed to the direction of wind. A troublesomeness of detecting the wind direction or a cost for a controller for adjusting the propeller to the wind direction is inconveniently required.
Further, as the usually known windmill device, a Savonius type windmill device as shown in FIG. 1 has been known. The Savonius type windmill device comprises a pair of upper and lower bottom plates 1 having disk shapes and a pair of plate type blade 2 having semicircular shapes in cross-section which are provided as shown in FIG. 1. This windmill device has a position (dead point) where the windmill device does not rotate due to a positional relation to a wind direction. That is, under a state shown in FIG. 1(A) (a state that wind is supplied to a position where both the blades 2 are superposed on each other), a clockwise rotating force by wind A (refer it to as a backward rotating force, hereinafter) and a counterclockwise rotating force by wind C (refer it to as a forward rotating force, hereinafter) are cancelled each other. Thus, the windmill device does not rotate. Further, under a state shown in FIG. 1(B), (a state that wind is supplied to the rear surface 2a of one blade 2), the backward rotating force by the wind A is strong, so that the rotating force of a desired direction (the forward rotating force) cannot be obtained. Accordingly, also in the Savonius type windmill device, the wind direction needs to be detected and the windmill device needs to be controlled to a state suitable for the wind direction like the above-described propeller type windmill device.
The applicant of the present invention already proposes a three blade type vertical windmill device shown in FIGS. 2 to 7 in the previously filed (Japanese Patent Application Lid-Open No. 2000-297637) in order to solve the inconveniences of the above-described usual windmill device.
In the three blade type vertical windmill device according to the previously filed application, a base 4 and an upper member 5 are fixed by a plurality (three in the case of an illustrated example) of supports 6. Between the base 4 and the upper member 5, three blades (blades 3A, 3B and 3C) which constitute a characteristic part of the present invention are provided. In the base 4, the above-described power generating means is provided. Further, in the upper member 5, various kinds of detecting means or control means (not shown) such as a wind power detector that is not shown in the drawings are provided. Various kinds of cords connected to the detecting means or the control means are extended outside from a take-out port 7 formed on the upper member 5.
Between the base 4, the upper member 5 and the supports 6, a pair of upper and lower bottom plates 8 and the three plate type blades 3A, 3B and 3C curved in their cross-section are disposed. Both the ends in the upper and lower parts of the three blades are respectively fixed to the pair of the bottom plates 8. On a center of the pair of the bottom plates 8, one vertical shaft 9 is provided integrally with each bottom plate 8. The vertical shaft 9 passes through the lower bottom plate 8 and is connected to the power generating means. The vertical shaft 9 transmits the rotating force of the above-described blades 3A, 3B and 3C to the power generating means.
The three blades 3A, 3b and 3C are disposed, as shown in FIGS. 5 to 7, under states that one side ends 3c are remote from the center O of the bottom plate 8 and the other side ends 3d are near to the center O. Distances R2 from the one side ends 3c of the blades 3A, 3B and 3C to the center O are equal and distances R1 from the other side ends 3d of the blades 3A, 3B and 3C to the center O are equal to one another between the blades 3A, 3B and 3C. The three blades 3A, 3B and 3C are located at equal intervals. The other side end part of one blade (for instance, the blade 3A) of the mutually adjacent blades (for instance the blades 3A and 3B) and the one side end part of the other blade (for instance, the blade 3B) whose one side end part is located outside the other side end part of the one blade (for instance, the blade 3A) form a wind inlet port 10.
The windmill device according to the previously filed application that is constructed as described above does not need to take the wind direction into consideration, which is different from each of the usual windmill devices as described above, and can be inexpensively produced with a simple structure. Specifically, as shown in FIG. 7(A), winds C and D collide with the back surface 3a of the blade 3A and reach the inner surface 3a of the blade 3B by the back surface 3a of the blade 3A to generate a forward rotating force. Further, wind E directly collides with the inner surface 3b of the blade 3B to similarly generate a forward rotating force. The winds C, D and E further move along the inner surface 3b of the blade 3B and collide with the inner surface 3b of the blade 3C to generate a forward rotating force. On the other hand, winds A and B collide with the blade 3C to generate a backward rotating force. However, the backward rotating force is adequately lower than the forward rotating force by the winds C, D and E. Accordingly, the windmill device efficiently rotates forward. The above-described phenomenon may be applied to a case in which wind blows from any direction. In other words, this windmill device is not affected by the wind direction even when wind blows from any direction and can efficiently obtain the rotating force.
Therefore, when the windmill device according to the previously filed application is fixed at a suitable position, even when wind blows from any direction, the above-described blades 3A, 3B and 3C assuredly rotate in a desired direction (a forward direction) so that a power can be effectively assuredly generated.
It is an object of the present invention is to provide an improved three blade type vertical windmill device in which a power generation efficiency by using the wind power of the three blade type vertical windmill device previously proposed by the applicant of the present invention can be greatly improved with a simple structure.